Area Forecast Discussion

WHAT HAS CHANGED

No major changes were made to the forecast.

KEY MESSAGES

1) Scattered showers shifting southward today

2) Continued warm with periodic shower chances late week into the weekend. Stronger cold front possible by Tuesday.

DISCUSSION

KEY MESSAGE 1...

A weak cold front/surface trough was analyzed across southern Michigan through southern Ontario. This front will sink slowly southward through the day, with scattered showers. The 00Z PIT sounding shows dry air in place from the surface through around 600mb, so the column will need to moisten some before rain reaches the ground. There could be an isolated thunderstorm, though instability is expected to remain limited (less than 500 j/kg ML CAPE.)

Most of the shower activity should be south of PIT during the day as the front continues southward, before stalling across southern PA/southern OH. QPF is progged to remain light, with most locations seeing a tenth of an inch or less.

KEY MESSAGE 2...

The stalled front is expected to be located across souther PA/OH Thursday, as ridging builds in aloft. There could be an isolated shower mainly south of PIT, though most locations should remain dry. The front is progged to lift back north as a warm front on Friday. Upper support and moisture is limited, though a few showers and isolated thunderstorms will be possible with weak ascent along the front.

A quasi zonal flow is expected to set up across much of the CONUS by Saturday. A shortwave embedded in the flow, and a surface low/cold front, is expected to approach and cross the Upper Ohio Valley region Friday night into Saturday. More widespread showers are expected as this system tracks across the area. There could also be a few thunderstorms, though instability is expected to be limited (ML CAPE <500 j/kg) with minimal shear as well. Some uncertainty exists in how fast the surface low and cold front will move east of the area on Saturday. Maintained a model blend of POPs through the day, though if the faster scenarios were to happen, POPs could be further reduced in the afternoon. Generally dry weather returns Sunday and Monday before a stronger trough and surface cold front approaches and crosses the region Monday night into Tuesday.

Temperatures are expected to warm Thursday and Friday, with readings generally 10-15 degrees above average. More seasonable temperatures are then expected for the weekend with the passage of the cold front.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

VFR is expected to prevail with high confidence through 05Z with occasional shear. Chances of restrictions increase from the northwest as a weather system approaches with embedded showers and low moisture. This will allow each port to have a chance of showers for 4-6hrs. Timing tracked the latest guidance from as early as 05Z at FKL to as late as 13Z at MGW. This may bring some brief vis drops; chances of thunder (<30% overnight) are low, but non- zero. No mentions for now.

Chances of cig drops increase behind the showers with added low level moisture, though IFR chances are only >80% at FKL/DUJ, while chances of at least MVFR elsewhere sit at >70%. Restriction chances are most confined to the 12Z to 18Z window. Scattering and lifting is favored into Wednesday, save some low probabilities of afternoon shower development at ZZV/MGW closer to the stalled boundary. Winds are expected to orient more northwesterly with gusts forecast less than 15kts.

Outlook... VFR is favored through the end of the work week. Another cold front brings rain chances and restrictions back to the area late Friday into the weekend.

PBZ WATCHES / WARNINGS / ADVISORIES

PA...None. OH...None. WV...None.